import uuid
import simplejson as json
import datetime

import redis  # used for collections

from gn2.utility.hmac import hmac_creation


def get_redis_conn():
    Redis = redis.StrictRedis(port=6379)
    return Redis


Redis = get_redis_conn()


def is_redis_available():
    try:
        Redis.ping()
    except:
        return False
    return True


def load_json_from_redis(item_list, column_value):
    if type(column_value) == str:
        column_value = str.encode(column_value)
    try:
        return json.loads(item_list[column_value])
    except:
        return None


def get_user_id(column_name, column_value):
    user_list = Redis.hgetall("users")
    key_list = []
    for key in user_list:
        user_ob = json.loads(user_list[key])
        if column_name in user_ob and user_ob[column_name] == column_value:
            return key

    return None


def get_user_by_unique_column(column_name, column_value):
    item_details = None

    user_list = Redis.hgetall("users")
    if column_name != "user_id":
        for key in user_list:
            user_ob = json.loads(user_list[key])
            if column_name in user_ob and user_ob[column_name] == column_value:
                item_details = user_ob
    else:
        item_details = load_json_from_redis(user_list, column_value)

    return item_details


def set_user_attribute(user_id, column_name, column_value):
    user_info = json.loads(Redis.hget("users", user_id))
    user_info[column_name] = column_value

    Redis.hset("users", user_id, json.dumps(user_info))


def get_user_collections(user_id):
    collections = None
    collections = Redis.hget("collections", user_id)

    if collections:
        return json.loads(collections)
    else:
        return []


def save_user(user, user_id):
    Redis.hset("users", user_id, json.dumps(user))


def save_collections(user_id, collections_ob):
    Redis.hset("collections", user_id, collections_ob)


def save_verification_code(user_email, code):
    Redis.hset("verification_codes", code, user_email)


def check_verification_code(code):
    email_address = None
    user_details = None
    email_address = Redis.hget("verification_codes", code)

    if email_address:
        user_details = get_user_by_unique_column(
            'email_address', email_address)
        if user_details:
            return user_details
        else:
            return None
    else:
        return None


def get_user_groups(user_id):
    # Get the groups where a user is an admin or a member and
    # return lists corresponding to those two sets of groups
    admin_group_ids = []  # Group IDs where user is an admin
    user_group_ids = []  # Group IDs where user is a regular user
    groups_list = Redis.hgetall("groups")
    for group_id, group_details in groups_list.items():
        try:
            _details = json.loads(group_details)
            group_admins = set([this_admin if this_admin else None for this_admin in _details['admins']])
            group_members = set([this_member if this_member else None for this_member in _details['members']])
            if user_id in group_admins:
                admin_group_ids.append(group_id)
            elif user_id in group_members:
                user_group_ids.append(group_id)
            else:
                continue
        except:
            continue

    admin_groups = []
    user_groups = []
    for the_id in admin_group_ids:
        admin_groups.append(get_group_info(the_id))
    for the_id in user_group_ids:
        user_groups.append(get_group_info(the_id))

    return admin_groups, user_groups


def get_group_info(group_id):
    group_json = Redis.hget("groups", group_id)
    group_info = None
    if group_json:
        group_info = json.loads(group_json)

    return group_info


def create_group(admin_user_ids, member_user_ids=[],
                 group_name="Default Group Name"):
    group_id = str(uuid.uuid4())
    new_group = {
        "id": group_id,
        "admins": admin_user_ids,
        "members": member_user_ids,
        "name": group_name,
        "created_timestamp": datetime.datetime.utcnow().strftime('%b %d %Y %I:%M%p'),
        "changed_timestamp": datetime.datetime.utcnow().strftime('%b %d %Y %I:%M%p')
    }

    Redis.hset("groups", group_id, json.dumps(new_group))

    return new_group


def delete_group(user_id, group_id):
    # ZS: If user is an admin of a group, remove it from the groups hash
    group_info = get_group_info(group_id)
    if user_id in group_info["admins"]:
        Redis.hdel("groups", group_id)
        return get_user_groups(user_id)
    else:
        None


# ZS "admins" is just to indicate whether the users should be added to
# the groups admins or regular users set
def add_users_to_group(user_id, group_id, user_emails=[], admins=False):
    group_info = get_group_info(group_id)
    # ZS: Just to make sure that the user is an admin for the group,
    # even though they shouldn't be able to reach this point unless
    # they are
    if user_id in group_info["admins"]:
        if admins:
            group_users = set(group_info["admins"])
        else:
            group_users = set(group_info["members"])

        for email in user_emails:
            user_id = get_user_id("email_address", email)
            group_users.add(user_id)

        if admins:
            group_info["admins"] = list(group_users)
        else:
            group_info["members"] = list(group_users)

        group_info["changed_timestamp"] = datetime.datetime.utcnow().strftime(
            '%b %d %Y %I:%M%p')
        Redis.hset("groups", group_id, json.dumps(group_info))
        return group_info
    else:
        return None


# ZS: User type is because I assume admins can remove other admins
def remove_users_from_group(user_id,
                            users_to_remove_ids,
                            group_id,
                            user_type="members"):
    group_info = get_group_info(group_id)

    if user_id in group_info["admins"]:
        users_to_remove_set = set(users_to_remove_ids)
        # ZS: Make sure an admin can't remove themselves from a group,
        # since I imagine we don't want groups to be able to become
        # admin-less
        if user_type == "admins" and user_id in users_to_remove_set:
            users_to_remove_set.remove(user_id)
        group_users = set(group_info[user_type])
        group_users -= users_to_remove_set
        group_info[user_type] = list(group_users)
        group_info["changed_timestamp"] = datetime.datetime.utcnow().strftime(
            '%b %d %Y %I:%M%p')
        Redis.hset("groups", group_id, json.dumps(group_info))


def change_group_name(user_id, group_id, new_name):
    group_info = get_group_info(group_id)
    if user_id in group_info["admins"]:
        group_info["name"] = new_name
        Redis.hset("groups", group_id, json.dumps(group_info))
        return group_info
    else:
        return None


def get_resources():
    resource_list = Redis.hgetall("resources")
    return resource_list


def get_resource_id(dataset, trait_id=None):
    resource_id = False
    if dataset.type == "Publish":
        if trait_id:
            resource_id = hmac_creation("{}:{}:{}".format(
                'dataset-publish', dataset.id, trait_id))
    elif dataset.type == "ProbeSet":
        resource_id = hmac_creation(
            "{}:{}".format('dataset-probeset', dataset.id))
    elif dataset.type == "Geno":
        resource_id = hmac_creation(
            "{}:{}".format('dataset-geno', dataset.id))

    return resource_id


def get_resource_info(resource_id):
    resource_info = Redis.hget("resources", resource_id)
    if resource_info:
        return json.loads(resource_info)
    else:
        return None


def add_resource(resource_info, update=True):
    if 'trait' in resource_info['data']:
        resource_id = hmac_creation('{}:{}:{}'.format(
            str(resource_info['type']), str(
                resource_info['data']['dataset']),
            str(resource_info['data']['trait'])))
    else:
        resource_id = hmac_creation('{}:{}'.format(
            str(resource_info['type']), str(resource_info['data']['dataset'])))

    if update or not Redis.hexists("resources", resource_id):
        Redis.hset("resources", resource_id, json.dumps(resource_info))

    return resource_info


def add_access_mask(resource_id, group_id, access_mask):
    the_resource = get_resource_info(resource_id)
    the_resource['group_masks'][group_id] = access_mask

    Redis.hset("resources", resource_id, json.dumps(the_resource))

    return the_resource
